A plane mirror is placed along the X-axis facing negative Y-axis. The mirror is fixed. A point object is moving with 3 hat i +4 hat j infront of the plane mirror. The relative velocity of image with respect to its object is

Question

A plane mirror is placed along the X-axis facing negative Y-axis. The mirror is fixed. A point object is moving with 3 hat i +4 hat j infront of the plane mirror. The relative velocity of image with respect to its object is (A) -8 hat j  (B) 8 hat j  (C) 3 hat i -4 hat j  (D) -6 hat j

Tardigrade Admin · Accepted Answer

Velocity of object, v ob =3 hat i +4 hat j Velocity of image, v text image =3 hat i -4 hat j Relative velocity of image with respect to its object v text rel =v text image -v ob =(3 hat i -4 hat j )-(3 hat i +4 hat j )=-8 hat j

Q. A plane mirror is placed along the $X$ -axis facing negative $Y$ -axis. The mirror is fixed. A point object is moving with $3 \hat{i} + 4 \hat{j}$ infront of the plane mirror. The relative velocity of image with respect to its object is

$- 8 \hat{j}$

$8 \hat{j}$

$3 \hat{i} - 4 \hat{j}$

$- 6 \hat{j}$

Velocity of object, $v_{o b} = 3 \hat{i} + 4 \hat{j}$
Velocity of image, $v_{image} = 3 \hat{i} - 4 \hat{j}$
Relative velocity of image with respect to its object
$v_{rel} = v_{image} - v_{o b} = (3 \hat{i} - 4 \hat{j}) - (3 \hat{i} + 4 \hat{j}) = - 8 \hat{j}$

Q. A plane mirror is placed along the X-axis facing negative Y-axis. The mirror is fixed. A point object is moving with 3i^+4j^​ infront of the plane mirror. The relative velocity of image with respect to its object is

−8j^​

8j^​

3i^−4j^​

−6j^​